The invention relates to a fuel supply system as described herein and finally claimed. A fuel supply system is already known in which, imprecision on the part of the pressure control valve which controls the pressure of the pressure fluid causes undesirable variations in the restoring force. It is also known to provide a pressure control valve in the fuel supply line, at which valve the fuel pressure upstream of the fuel apportionment valve prevails on one side and the air pressure upstream of the air flow rate meter prevails on the otherside. It is further known to supply air to the apportioned fuel downstream of the fuel apportionment valve, under the pressure of the air intake line upstream of the air flow rate meter.